OAKLAND -- This isn't ironic, merely weird: The A's enter their fourth consecutive playoff series tonight looking for their first recent advance beyond the infant stage, and -- stop me if you've heard this before -- they're leaning heavily on a fine infielder who is ... (Pause for dramatic effect) ...

About to leave. Call it small-market syndrome, Moneyball Madness, the curse of Steve Schott, whatever. But even in an era in which rent-a-stick ballplayers have become commonplace, and impermanence is the watchword of the month (pick a month, any month), the impending departure of free-agent-to-be Miguel Tejada strikes a nerve.

Where? Well, right about third base, for starters.

It is over there that Tejada's partner in grime on the left side of the infield, Eric Chavez, has spent the last few days dealing with the reality that these October games may be the last he plays alongside the shortstop they call "Miggy."

"It's going to be tough," Chavez said Tuesday, just after the A's finished their final workout before facing Pedro Martínez and the Boston Red Sox tonight in Game 1 of the American League Division Series. "Miggy gets to so many balls, and he's gone from being an everyday player to being 'The Guy.'

"He's such a big part of this team. Of all the guys that we're going to lose, he's going to be the one that really hurts. And we're going to find that out next year when he's not here."

But that is still "if" Tejada isn't around, right? After all, the free-agent period doesn't begin for weeks now. Or is Chavez simply bracing himself with a worst-case scenario?

"He's not gonna be here," Chavez replied. "I mean, that's what they told us, right? When the boss tells you somebody's not gonna be here, why should you believe otherwise?"

You know what? It's a terrific question.

Schott and the rest of the A's brass weren't as openly discouraging on the subject of Jason Giambi two falls ago. As Giambi played what proved to be his final series with Oakland, losing in the playoffs to a Yankees team he ultimately would join as a pricey free agent, he did so in an atmosphere of at least reasonable uncertainty about his future.

Tejada takes the field tonight in a truly different circumstance. For one, his A's now are four-October veterans, with three stinging first-round exits motivating them to jump on the Red Sox and never let up. It's a young team but a veteran one, the kind of combination that general managers dream of, when they're not spending their waking hours trying to figure how to keep one together.

For another, of course, there's the whole Schott angle. The owner took the unusual (some would say understandably unprecedented) step of announcing in spring training that the A's would not be making a contract offer to Tejada, on the grounds that they didn't want to insult such an esteemed player with a low-ball offer.

Debate the merits of that all you want -- is a little insult such a bad thing? -- but the wheels were put into motion. Schott has since retreated a bit, and Tejada has said he's always open to new ideas, but no one in the clubhouse buys it. Playing in Oakland usually means saying goodbye to someone great, sooner if not later.

Tejada said Tuesday he already has spoken with Boston's Martínez, a friend for whom he has great respect, about his pending free agency. He will speak with Giambi, likewise a friend, and a player who basically has lived this part of the baseball life already.

And where that leaves the shortstop, just now, is in the position of simply wanting to finish the job in Oakland. He wants to atone for his awful playoff performance against the Twins last year, when the American League's Most Valuable Player batted just .143.

Perhaps he even wants to leave a legacy, as the player who helped drag the A's of the Billy Beane era onward toward a pennant.

There's a whole lot of leaving in the air, now that we mention it.

"I didn't hit in the playoffs last year," Tejada said. "But that's in the past. Now we're going to play another team, a new city. The season's over -- a new series starts. Let's see who plays better baseball."

It has to be Tejada, of course. It has to be Tejada and Chavez. The A's have pitching, and the Red Sox have hitting, but the other side of that coin is blazingly obvious. If Oakland is going to score enough to beat Boston, it will be because its two primary offensive threats came through.

Two years ago, it was Chavez who struggled, batting .143 against the New York Yankees and failing repeatedly in clutch situations. A year ago, Tejada pronounced himself "really embarrassed" after collecting just three hits in five games against Minnesota.

Now comes the fall of 2003, and it is Tejada and Chavez once more. Together again. Don't write that down in permanent ink.